A transgenic, non-human mammal useful for assessing the effect of candidate chemotherapeutic
drugs on the growth of brain tumors in vivo is provided. Incorporated into the
genome of the transgenic mammal, which preferably is a rodent, is a transgene which
comprises a promoter comprising the nuclear factor binding region of the RR2 cis
acting element of a fibroblast growth factor 1B (FGF1B) promoter. Operably linked
to the promoter is reporter gene comprising a sequence which encodes the SV40 large
T antigen. A transgenic, non-human mammal useful for identifying and isolating
FGF1 producing brain cells. Incorporated into the genome of these transgenic animals
is a transgene which comprises a promoter comprising the nuclear factor binding
region of the RR2 cis acting element of an fibroblast growth factor 1B (FGF1B)
promoter. Operably linked to the promoter is reporter gene comprising a sequence
which encodes a protein or polypeptide other than an SV40 large T antigen. A method
of obtaining neural stem cells from a sample of cells obtained from an animal is
also provided. Such method comprises introducing the FGF1B-detector transgene into
a sample of cells that have been obtained from the animal, and assaying for expression
of the detectable marker in the cells, wherein cells that express the marker are
neural stem cells. The cells which express the detectable marker can then be isolated
from the population to provide a sub-population of neural stem cells.